Some radio stations play out media, e.g., a reading of a book excerpt, during a radio broadcast. Radio listeners who desire to purchase a corresponding media object, e.g., a book or an e-book, must listen to identifying information associated with the media object, and then recall the identifying information at a later time in order to purchase the media object. Even if the radio listener hears, and later is able to recall the identifying information, the radio listener may not be able to access the desired media object on-demand, for example, the listener may be in a moving vehicle). Other audio sources besides radios may play out media, which may be also need to be identified for purchase or for other reasons.